Molten salt uniform heating device and method

Abstract

The invention provides a molten salt uniform heating device and method, and belongs to the technical field of molten salt heating. The molten salt uniform heating device comprises an induction heater, a metal block, a temperature sensor and a memory alloy; the induction heater is annularly arranged and is fixedly mounted on the pipe wall of the flowing pipeline; the metal block body is installed in the heating area and fixedly connected with the inner wall of the flowing pipeline, and a conical hole and a spiral flowing seam are formed in the metal block body; the temperature sensor is installed on the metal block and used for monitoring the temperature of the metal block. The temperature sensor is in communication connection with the control module of the induction heater; the memory alloy is annularly arranged and is fixedly mounted on the lower end surface of the metal block body; the upper end of the memory alloy is in butt joint with a lower hole opening of the conical hole. The memory alloy deforms to vary the effective flow area. According to the molten salt uniform heating device provided by the invention, the separation of a turbulent flow function and a reducing function is realized, and the heating uniformity of the molten salt is greatly improved.

Description

Technical Field

[0001] This application belongs to the field of molten salt heating technology, and more specifically, relates to a molten salt uniform heating device and method. Background Technology

[0002] In many industrial fields such as concentrated solar power generation and chemical heating, molten salt is widely used as a heat transfer and storage medium due to its unique advantages, including good high-temperature stability, high heat transfer and storage efficiency, and low corrosivity. Currently, in existing molten salt electromagnetic induction heating devices, in order to achieve variable diameter adaptation and enhanced heating effect through fluid turbulence within the molten salt pipeline, a structural design with built-in shape memory alloy elements is typically adopted. These shape memory alloy elements must simultaneously undertake the two core functions of variable diameter adjustment and fluid turbulence.

[0003] However, the structural deformation of shape memory alloy components is entirely driven by temperature changes. The deformation process occurs continuously with temperature fluctuations, making it impossible to maintain a stable structural state. Consequently, the turbulence intensity fluctuates with temperature changes, making it impossible to independently design and maintain a constant turbulence intensity. This results in uneven flow field distribution of molten salt fluid in the pipe, ultimately affecting heating uniformity and making it difficult to meet the uniformity, stability, and reliability requirements of molten salt heating. Summary of the Invention

[0004] The purpose of this application is to provide a molten salt uniform heating device and method to solve the technical problems of insufficient uniformity and stability in the molten salt heating process in the prior art.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide a molten salt uniform heating device for installation in a flow pipeline, comprising: An induction heater is arranged in a ring and fixedly installed on the wall of the flow pipe; a heating zone is formed inside the flow pipe within the induction heater; A metal block is installed in the heating zone and fixedly connected to the inner wall of the flow pipe; the metal block is provided with a conical hole that is larger at the top and smaller at the bottom and is arranged through the hole; the metal block is provided with a number of spiral flow slots opened on the conical hole, and the spiral flow slots form a secondary flow for molten salt flow; A temperature sensor is installed on the metal block to monitor the temperature of the metal block; the temperature sensor is communicatively connected to the control module of the induction heater. A shape memory alloy is arranged in a ring and fixedly installed on the lower end face of the metal block; the upper end of the shape memory alloy is connected to the lower opening of the tapered hole; the shape memory alloy deforms to change the effective flow area.

[0006] In one possible implementation, an annular groove is formed inside the wall of the flow pipe, and the induction heater is fixedly installed in the annular groove.

[0007] In one possible implementation, the upper end of the induction heater is higher than the upper end of the metal block, and the lower end of the induction heater is lower than the lower end of the metal block.

[0008] In one possible implementation, the upper orifice diameter of the tapered hole is equal to the outer diameter of the metal block.

[0009] In one possible implementation, the tapered hole includes a tapered hole section and a straight hole section arranged sequentially from top to bottom, with the upper end of the shape memory alloy being butt-mounted within the straight hole section.

[0010] In one possible implementation, the number of spiral flow slots is multiple, and they are evenly spaced along the circumferential intervals of the conical hole.

[0011] In one possible implementation, the spiral flow slit has a slit depth of 0.5-1.5 mm, a slit width of 0.5-1 mm, and a spiral angle of 20-40°.

[0012] In one possible implementation, there are multiple induction heaters, metal blocks, temperature sensors, and shape memory alloys, arranged in multiple groups; the multiple induction heaters are arranged sequentially at intervals along the axial direction of the flow pipe.

[0013] In one possible implementation, the temperature sensor is positioned close to the lower opening of the tapered hole.

[0014] The beneficial effects of the molten salt uniform heating device provided in this application are as follows: Compared with the prior art, the molten salt uniform heating device of this application separates the turbulence function and the diameter change function, and achieves uniform and stable heating of molten salt through the coordinated work of each component.

[0015] The induction heater is arranged in a ring and fixed on the wall of the flow pipe, forming a heating zone inside the pipe. The ring design enables the molten salt inside the pipe to be heated in a surrounding manner, ensuring a comprehensive heating range and avoiding the problem of uneven local heating.

[0016] The metal block is installed in the heating zone and fixedly connected to the inner wall of the pipe. As the core component for turbulence and support, it has a tapered hole that is larger at the top and smaller at the bottom that runs through the entire pipe. At the same time, several spiral flow slots are provided on the tapered hole. The structure of the tapered hole, which is larger at the top and smaller at the bottom, can guide the molten salt to flow smoothly through the heating zone and reduce flow resistance. The spiral flow slots can make the molten salt form a secondary flow during the flow process, thereby achieving stable turbulence and enhancing the heat exchange efficiency between the molten salt and the heating zone and the metal block. This design concentrates the turbulence function on the tapered hole and spiral flow slots of the metal block, completely separating it from the diameter change function of the shape memory alloy, and solving the problem of turbulence intensity fluctuating with temperature in the prior art.

[0017] A temperature sensor is installed on the metal block to monitor the temperature of the heat exchange molten salt in real time. It is also connected to the control module of the induction heater to transmit the monitored temperature signal to the control module in a timely manner, thereby enabling precise adjustment of the heating power and ensuring stable temperature in the heating zone.

[0018] The shape memory alloy is arranged in a ring and fixed on the lower end face of the metal block. Its upper end is connected to the lower opening of the conical hole. It only undertakes the function of diameter change adaptation. It changes the effective flow area by its own deformation. It does not need to participate in the turbulence and avoids the influence of deformation on the turbulence effect due to temperature fluctuations.

[0019] When molten salt flows through the device along the flow pipe, it first enters the tapered hole (larger at the top, smaller at the bottom) of the metal block. Guided by the tapered hole, it smoothly enters the heating zone. As it flows through the spiral flow slots on the tapered hole, a secondary flow is formed, creating a stable turbulence effect. This ensures the molten salt fully contacts the heating zone and the metal block, achieving uniform heating. Simultaneously, the shape memory alloy deforms according to the temperature of the metal block and the molten salt, thereby changing its effective flow area to adapt to different flow rates and operating conditions. During operation, a temperature sensor monitors the temperature of the metal block in real time and continuously transmits the temperature data to the control module of the induction heater. The control module automatically adjusts the heating power of the induction heater based on a preset molten salt heating temperature threshold and the real-time data transmitted by the temperature sensor, ensuring that the temperature of the metal block and the heating zone remains stable within a reasonable range and avoiding excessive temperature fluctuations.

[0020] This method separates the turbulence function from the diameter change function. The turbulence is achieved by the spiral flow slots and conical holes on the metal block. The structure is fixed, the turbulence intensity is constant and can be designed independently, which solves the problems of turbulence intensity fluctuating with temperature and uneven flow field distribution in the existing technology, and greatly improves the uniformity of molten salt heating.

[0021] Another object of this application is to provide a method for uniformly heating molten salt, employing any one of the above-mentioned molten salt uniform heating devices, comprising: S1: Activate the induction heater to heat the metal block; S2: Molten salt enters the flow pipe and falls onto the conical hole, forming a vortex motion. Molten salt also enters the spiral flow slot to form a constant secondary flow, making the molten salt heat evenly. S3: When the temperature inside the flow channel is higher than the threshold, the shape memory alloy deforms inward to reduce the flow channel area and prolong the residence time of the molten salt for heat exchange; when the temperature is lower than the threshold, the shape memory alloy deforms outward to increase the flow area and reduce the residence time of the molten salt for heat exchange. S4: The temperature sensor collects the temperature of the metal block and feeds the signal back to the control module. The control module adjusts the input power of the induction heater so that the temperature difference in the flow pipe is ≤±1℃.

[0022] The molten salt uniform heating method provided in this application adopts a molten salt uniform heating device. Relying on the aforementioned molten salt uniform heating device, a closed-loop process of starting heating, turbulent heat exchange, diameter adjustment, and precise temperature control is used to achieve efficient, stable, and precise heating of molten salt.

[0023] In specific operation, the induction heater in the device is first started. Since the induction heater is fixed in a ring on the wall of the flow pipe, it can quickly generate heat and transfer it to the metal block after starting, so that the metal block can quickly heat up to the preset heat exchange temperature, providing a stable heat source for subsequent molten salt heating. This step ensures that the temperature of the metal block reaches the standard quickly through the high efficiency of induction heating, thus preparing for molten salt heat exchange.

[0024] Subsequently, the molten salt enters the flow pipe at a preset flow rate. As it flows past the metal block, it falls onto the tapered holes, which are wider at the top and narrower at the bottom. The special structure of the tapered holes guides the molten salt to naturally form vortex motion. At the same time, some of the molten salt enters the spiral flow slots evenly arranged around the tapered holes, forming a secondary flow of constant intensity. The vortex and the secondary flow work together to break the laminar flow state of the molten salt, allowing the molten salt to fully and evenly contact the heated metal block and the heating zone formed by the induction heater. This avoids insufficient heating due to excessively fast local flow of the molten salt, or overheating due to excessive local residence. This achieves the initial uniform heating of the molten salt. This step utilizes a constant turbulence structure to ensure the uniformity of molten salt heating, echoing the design advantage of separating the turbulence and diameter variation functions in the device.

[0025] By leveraging the temperature deformation characteristics of shape memory alloys, the flow channel area can be adaptively adjusted without manual intervention, responding completely automatically to temperature changes. When the temperature inside the flow channel exceeds a certain threshold, it indicates that the molten salt is overheated. In this case, the shape memory alloy will deform inward due to the increased temperature, thereby reducing the effective area of ​​the molten salt flow channel and extending the residence time of the molten salt in the heating zone, preventing local overheating. When the temperature inside the channel is below the preset threshold, the shape memory alloy will deform outward due to the decreased temperature, increasing the effective area of ​​the flow channel and shortening the residence time of the molten salt, preventing underheating. Through this adaptive adjustment, precise matching between the molten salt heat exchange time and temperature is achieved.

[0026] A temperature sensor continuously collects the real-time temperature of the metal block (the temperature of the metal block is highly synchronized with the temperature of the molten salt in the pipe, accurately reflecting the heating status of the molten salt) and feeds the collected temperature signal back to the control module of the induction heater in real time. The control module analyzes and processes the received signal, compares it with a preset temperature threshold, and automatically adjusts the input power of the induction heater. When the temperature is too high, the input power is reduced; when the temperature is too low, the input power is increased, ultimately ensuring that the temperature difference in the flow pipe is controlled within the range of ≤±1℃, achieving constant temperature and uniform heating of the molten salt.

[0027] In this way, relying on the spiral flow slot and conical hole structure, stable vortices and constant secondary flows are formed in the molten salt, solving the problem of uneven heating caused by unstable turbulence intensity in existing methods and improving the uniformity of molten salt heating. By using the adaptive deformation adjustment of the flow channel area of ​​the shape memory alloy, the residence time of the molten salt for heat transfer is automatically matched without manual intervention, reducing the difficulty of operation. At the same time, it adapts to the molten salt heating requirements under different temperature conditions, improving the adaptability of the method. Meanwhile, the closed-loop control of the temperature sensor and control module keeps the temperature difference in the pipeline within ±1℃, achieving precise control of the molten salt temperature and avoiding the impact of excessive temperature fluctuations on the performance of the molten salt and subsequent production. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 Cross-sectional view of the molten salt uniform heating device provided in the embodiments of this application. Figure 1 ; Figure 2 Top view of the molten salt uniform heating device provided in the embodiments of this application. Figure 1 ; Figure 3 Cross-sectional view of the molten salt uniform heating device provided in the embodiments of this application. Figure 2 ; Figure 4 Top view of the molten salt uniform heating device provided in the embodiments of this application. Figure 2 .

[0030] The following are the labeling elements in the figure: 10. Induction heater; 20. Metal block; 21. Conical hole; 22. Spiral flow slot; 30. Temperature sensor; 40. Shape memory alloy; 50. Flow pipe. Detailed Implementation

[0031] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0032] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0033] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] Please see Figures 1 to 4The molten salt uniform heating device provided in this application will now be described. A molten salt uniform heating device, for installation in a flow pipe 50, includes an induction heater 10, a metal block 20, a temperature sensor 30, and a shape memory alloy 40; the induction heater 10 is arranged in a ring and fixedly installed on the wall of the flow pipe 50; a heating zone is formed inside the induction heater 10 and located within the flow pipe 50; the metal block 20 is installed in the heating zone and fixedly connected to the inner wall of the flow pipe 50; the metal block 20 has a conical hole 21 that is larger at the top and smaller at the bottom and is arranged through the pipe; the metal block 20... The metal block 20 has several spiral flow slots 22 formed on the conical hole 21, which form a secondary flow for molten salt flow. A temperature sensor 30 is installed on the metal block 20 to monitor the temperature of the metal block 20. The temperature sensor 30 is communicatively connected to the control module of the induction heater 10. The shape memory alloy 40 is arranged in a ring and fixedly installed on the lower end face of the metal block 20. The upper end of the shape memory alloy 40 is connected to the lower opening of the conical hole 21. The shape memory alloy 40 deforms to change the effective flow area.

[0036] The molten salt uniform heating device provided in this application, compared with the prior art, separates the turbulence function and the diameter change function, and achieves uniform and stable heating of molten salt through the coordinated work of various components.

[0037] The induction heater 10 is arranged in a ring and fixed on the wall of the flow pipe 50. It forms a heating zone inside the pipe. The ring design can realize the surrounding heating of the molten salt in the pipe, ensuring the heating range is comprehensive and avoiding the problem of uneven local heating.

[0038] The metal block 20 is installed in the heating zone and fixedly connected to the inner wall of the pipe. As the core component for turbulence and support, it has a tapered hole 21 that is larger at the top and smaller at the bottom that runs through it. At the same time, several spiral flow slots 22 are provided on the tapered hole 21. The structure of the tapered hole 21, which is larger at the top and smaller at the bottom, can guide the molten salt to flow smoothly through the heating zone and reduce flow resistance. The spiral flow slots 22 can make the molten salt form a secondary flow during the flow process, thereby achieving stable turbulence and enhancing the heat exchange efficiency between the molten salt and the heating zone and the metal block 20. This design concentrates the turbulence function on the tapered hole 21 and spiral flow slots 22 of the metal block 20, and completely separates it from the diameter change function of the shape memory alloy 40, thus solving the problem of turbulence intensity fluctuating with temperature in the prior art.

[0039] Temperature sensor 30 is installed on metal block 20 to monitor the temperature of heat exchange molten salt in metal block 20 in real time. It is also connected to the control module of induction heater 10 to transmit the monitored temperature signal to the control module in a timely manner, so as to achieve precise adjustment of heating power and ensure stable temperature in the heating zone.

[0040] The shape memory alloy 40 is arranged in a ring and fixed on the lower end face of the metal block 20. Its upper end is connected to the lower opening of the tapered hole 21. It only undertakes the function of diameter change adaptation. It changes the effective flow area by its own deformation. It does not need to participate in the turbulence and avoids the influence of temperature fluctuation on the turbulence effect.

[0041] When molten salt flows through the device along the flow pipe 50, it first enters the tapered hole 21 of the metal block 20, which is wider at the top and narrower at the bottom. Guided by the tapered hole 21, it smoothly enters the heating zone. When it flows through the spiral flow slot 22 on the tapered hole 21, it forms a secondary flow, generating a stable turbulence effect, allowing the molten salt to fully contact the heating zone and the metal block 20, achieving uniform heating. At the same time, the shape memory alloy 40 deforms according to the temperature of the metal block 20 and the molten salt, thereby changing its effective flow area to adapt to the molten salt flow requirements under different flow rates and operating conditions. During operation, the temperature sensor 30 monitors the temperature of the metal block 20 in real time and continuously transmits the temperature data to the control module of the induction heater 10. The control module automatically adjusts the heating power of the induction heater 10 according to the preset molten salt heating temperature threshold and compares it with the real-time data transmitted by the temperature sensor 30, ensuring that the temperature of the metal block 20 and the heating zone remains stable within a reasonable range and avoiding excessive temperature fluctuations.

[0042] This method separates the turbulence function from the diameter change function. The turbulence is achieved by the spiral flow slot 22 and the conical hole 21 on the metal block 20. The structure is fixed, the turbulence intensity is constant and can be designed independently, which solves the problems of turbulence intensity fluctuating with temperature and uneven flow field distribution in the prior art, and greatly improves the uniformity of molten salt heating.

[0043] The shape memory alloy 40 only serves the function of changing diameter and does not need to take into account the turbulence at the same time. Its deformation is only used to change the effective flow area and does not need to deform continuously with temperature. The structure is more stable. In addition, the spiral flow slot 22 on the metal block 20 is a fixed structure, which eliminates the need to design a spiral groove with variable depth. This greatly simplifies the processing technology, reduces the processing difficulty and manufacturing cost, and improves the operational reliability and service life of the device. The communication connection between the temperature sensor 30 and the control module of the induction heater 10 enables real-time monitoring and precise adjustment of the heating temperature, effectively avoiding overheating or underheating, further ensuring the stability of molten salt heating and reducing energy consumption. The induction heater 10 is an induction heating coil.

[0044] During operation, when the shape memory alloy 40 is heated, it will shrink and deform, thereby reducing the effective flow area of ​​the flow channel 50. At this time, the time that the molten salt stays in the flow channel 50 increases, thus increasing the convective heat transfer time inside the molten salt. At this time, the temperature inside the entire flow channel 50 will decrease, and the shape memory alloy 40 will rebound, thereby increasing the effective flow area of ​​the flow channel 50, achieving the purpose of controlling the molten salt temperature within the specified range.

[0045] Please see Figure 1 and Figure 3 As a specific embodiment of the molten salt uniform heating device provided in this application, an annular groove is formed inside the wall of the flow pipe 50, and the induction heater 10 is fixedly installed in the annular groove. First, an annular groove matching the size of the induction heater 10 is precisely formed along the circumference of the flow pipe 50 inside the pipe wall, ensuring that the inner wall of the groove is flat and the dimensional error meets the requirements. Then, the induction heater 10 is placed smoothly into the annular groove and firmly installed using high-temperature resistant fasteners to ensure that the heater fits tightly with the inner wall of the groove. After installation, the compatibility between the heater and the pipe is adjusted to avoid loosening.

[0046] The annular groove enables seamless contact between the induction heater 10 and the wall of the flow pipe 50, shortening the heat transfer path and making the pipe more evenly heated, thus ensuring uniform heating of the molten salt inside the pipe. At the same time, by embedding the heater inside, it can avoid being exposed to molten salt erosion or external environmental influences, extending its service life, saving external space of the pipe, improving the stability and safety of the device operation, and adapting to the working conditions of high-temperature molten salt heating.

[0047] Please see Figure 1 and Figure 3 As a specific embodiment of the molten salt uniform heating device provided in this application, the upper end of the induction heater 10 is higher than the upper end of the metal block 20, and the lower end of the induction heater 10 is lower than the lower end of the metal block 20. When installing the induction heater 10 and the metal block 20, accurately position their relative positions. First, fix the metal block 20 to the preset position, and then adjust the installation height of the induction heater 10 to ensure that its upper end exceeds the upper end of the metal block 20 and its lower end is lower than the lower end of the metal block 20, so that the induction heater 10 completely covers the heating area of ​​the metal block 20. After adjustment, fix both firmly and test the heating coverage area.

[0048] The induction heater 10 extends beyond the metal block 20 at both ends, enabling full-coverage heating of the metal block 20. This avoids heating dead zones at the top and bottom ends of the metal block 20, ensuring uniform heating of the entire metal block 20. Consequently, the heat transferred to the molten salt becomes more stable and uniform. At the same time, it expands the heating radiation range, improves heat utilization, reduces heat loss, and avoids heating deviations of the molten salt caused by uneven heating of the metal block 20 in certain areas.

[0049] Please see Figure 1 and Figure 3 As a specific embodiment of the molten salt uniform heating device provided in this application, the upper opening diameter of the conical hole 21 is equal to the outer diameter of the metal block 20. When machining the conical hole 21, its upper opening diameter is precisely controlled to ensure that its size is completely consistent with the outer diameter of the metal block 20. After machining, the upper opening of the conical hole 21 is ground to remove burrs and ensure smooth edges. Then, the lower end of the metal block 20 is precisely aligned with the upper opening of the conical hole 21, and a high-temperature resistant sealant is used to seal the connection. After secure fixing, the sealing performance and fit are checked.

[0050] The identical dimensions of both allow for seamless connection between the metal block 20 and the upper orifice of the conical hole 21, improving the sealing performance at the joint and effectively preventing leakage of molten salt from the joint gap during the flow process, thus ensuring the safe operation of the device. At the same time, the tight fit can shorten the heat transfer path, allowing the heat of the metal block 20 to be quickly and evenly transferred to the inner wall of the conical hole 21, and then transferred to the molten salt through the spiral flow slot 22, avoiding heat loss and improving heating uniformity and efficiency.

[0051] Please see Figure 1 and Figure 3 As a specific embodiment of the molten salt uniform heating device provided in this application, when processing the conical hole 21, the upper straight hole section and the lower conical hole section are processed sequentially according to the design dimensions to ensure that the two sections are smoothly connected, the inner wall is smooth, and the dimensional error meets the requirements. Then, the upper end of the shape memory alloy 40 is precisely inserted into the straight hole section, the position is adjusted to make it tightly connected, and the shape memory alloy 40 is fixed with a high temperature resistant fixing structure to ensure that there is no looseness. After installation, the flexibility of movement and the sealing of the connection of the shape memory alloy 40 are checked.

[0052] The straight-hole section provides a stable installation and positioning space for the shape memory alloy 40, facilitating precise docking and secure fixation, preventing displacement under molten salt impact, and ensuring stable temperature control. The connection between the tapered and straight-hole sections allows molten salt to flow smoothly from the tapered section into the straight-hole section, reducing flow resistance and extending the heating path of the molten salt, thus improving heating uniformity. Furthermore, the straight-hole section avoids direct contact between the shape memory alloy 40 and the inclined surface of the tapered section, reducing wear, extending the service life of the shape memory alloy 40, and ensuring the reliability of the device's temperature control.

[0053] Please see Figures 1 to 4As a specific embodiment of the molten salt uniform heating device provided in this application, there are multiple spiral flow slots 22, which are evenly arranged at intervals along the circumference of the conical hole 21. The processing positions of multiple spiral flow slots 22 are planned along the circumference at a preset uniform interval to ensure that the spacing error is consistent. Then, multiple spiral flow slots 22 are processed synchronously according to the design specifications to control the spiral trajectory, depth and width of the flow slots to be uniform. After processing, the smoothness and integrity of each flow slot are checked to ensure that there is no blockage or damage.

[0054] Multiple uniformly arranged spiral flow slots 22 can evenly distribute the molten salt, allowing it to flow evenly around the conical orifice 21, thus avoiding uneven heating caused by localized molten salt accumulation. Simultaneously, the spiral structure extends the flow path of the molten salt, increasing the contact time between the molten salt and the inner wall of the conical orifice 21, enabling the molten salt to fully absorb heat and improving heating uniformity. Furthermore, the uniform arrangement ensures more even heat transfer around the conical orifice 21, preventing localized overheating or insufficient heating.

[0055] As a specific embodiment of the molten salt uniform heating device provided in this application, the spiral flow slit 22 has a slit depth of 0.5-1.5mm, a slit width of 0.5-1mm, and a spiral angle of 20-40°. This parameter range has been optimized, with a moderate slit depth and width that ensures smooth flow of molten salt and avoids blockage, while also ensuring full contact between the molten salt and the inner wall of the flow slit, thereby improving heat absorption efficiency. The spiral angle of 20-40° can reasonably extend the flow path of the molten salt, while avoiding excessive flow resistance, achieving uniform and stable flow of molten salt, thus ensuring uniform heating of the molten salt and reducing local temperature deviations. The uniform parameters can make the heating effect of multiple flow slits consistent, further improving the overall heating uniformity and operational stability of the device.

[0056] Preferably, the spiral flow slit 22 has a slit depth of 1 mm, a slit width of 0.6 mm, and a spiral angle of 30°.

[0057] As a specific embodiment of the molten salt uniform heating device provided in this application, there are multiple induction heaters 10, metal blocks 20, temperature sensors 30, and shape memory alloys 40, arranged in multiple groups. Multiple induction heaters 10 are arranged sequentially at intervals along the axial direction of the flow pipe 50. The multiple induction heaters 10, metal blocks 20, temperature sensors 30, and shape memory alloys 40 are grouped one-to-one to ensure that each group of components has uniform specifications and good compatibility. Then, the multiple groups of components are arranged sequentially at preset intervals along the axial direction of the flow pipe 50, and each group is firmly fixed. The relative positions of each group of components are adjusted to ensure consistent heating and temperature control. After installation, the operating status of each group of components is tested to ensure normal coordinated operation.

[0058] Multiple sets of components are arranged at intervals along the pipeline axis, which can realize segmented heating and precise temperature control of molten salt within 50 of the flowing pipeline, avoiding excessive temperature gradient of molten salt caused by single-point heating, and ensuring that molten salt is continuously and uniformly heated during the flow process; each set of components works independently and cooperates with each other, and can accurately adjust the heating parameters of each section according to the temperature change in the direction of molten salt flow, thereby improving temperature control accuracy and heating efficiency.

[0059] Please see Figures 1 to 4 As a specific embodiment of the molten salt uniform heating device provided in this application, the temperature sensor 30 is set close to the lower opening of the conical hole 21. That is, when installing the temperature sensor 30, it is precisely positioned near the lower opening of the conical hole 21. The installation angle is adjusted to ensure that the sensor detection end can accurately capture the temperature of the molten salt after being heated and diverted through the conical hole 21. The sensor is firmly installed using high-temperature resistant fasteners to prevent it from shifting due to the impact of molten salt. After installation, the detection sensitivity and data transmission stability of the sensor are adjusted to ensure that the detection data is accurate and reliable.

[0060] The lower orifice of the conical hole 21 is a critical location where the molten salt enters the subsequent pipeline after heating and diversion. A temperature sensor 30 is installed here to detect the actual temperature of the molten salt after heating in real time and accurately, and to provide timely feedback on the temperature data. This allows for quick adjustment of the heating parameters of the induction heater 10 based on the detection results, preventing the molten salt temperature from being too high or too low, ensuring the uniformity of molten salt heating, and also enabling timely detection of temperature abnormalities and early warning of faults.

[0061] Please see Figures 1 to 4 This application also provides a method for uniformly heating molten salt, wherein the method employs any one of the above-mentioned molten salt uniform heating devices, and includes: S1: Start the induction heater 10 to heat the metal block 20; S2: Molten salt enters the flow pipe 50 and falls on the conical hole 21 to form a vortex motion. Molten salt enters the spiral flow slot 22 to form a constant secondary flow, so that the molten salt is heated evenly. S3: When the temperature inside the flow channel 50 is higher than the threshold, the shape memory alloy 40 deforms inward to reduce the flow channel area and prolong the residence time of the molten salt for heat exchange; when the temperature is lower than the threshold, the shape memory alloy 40 deforms outward to increase the flow area and reduce the residence time of the molten salt for heat exchange. S4: Temperature sensor 30 collects the temperature of metal block 20 and feeds the signal back to control module. Control module adjusts input power of induction heater 10 to make the temperature difference in flow pipe 50 ≤ ±1℃.

[0062] The molten salt uniform heating method provided in this application embodiment relies on the aforementioned molten salt uniform heating device to achieve efficient, stable, and precise heating of molten salt through a closed-loop process of starting heating, turbulent heat exchange, variable diameter adjustment, and precise temperature control.

[0063] In specific operation, the induction heater 10 in the device is started first. Since the induction heater 10 is fixed in a ring on the wall of the flow pipe 50, it can quickly generate heat after starting and transfer it to the metal block 20, so that the metal block 20 can be heated up quickly to the preset heat exchange temperature, providing a stable heat source for subsequent molten salt heating. This step ensures that the temperature of the metal block 20 reaches the standard quickly through the high efficiency of induction heating, thus preparing for molten salt heat exchange.

[0064] Subsequently, the molten salt enters the flow pipe 50 at a preset flow rate. When it flows through the metal block 20, it falls onto the tapered hole 21, which is larger at the top and smaller at the bottom. The special structure of the tapered hole 21 can guide the molten salt to naturally form a vortex motion. At the same time, some of the molten salt will enter the spiral flow slots 22 that are evenly arranged around the tapered hole 21, forming a secondary flow of constant intensity. The vortex and the secondary flow work together to break the laminar flow state of the molten salt, so that the molten salt can fully and evenly contact the heated metal block 20 and the heating zone formed by the induction heater 10. This avoids the molten salt from flowing too fast locally, resulting in insufficient heating, or from staying in one place for too long, resulting in overheating. This achieves the initial uniform heating of the molten salt. This step uses a constant turbulence structure to ensure the uniformity of molten salt heating, echoing the design advantage of separating the turbulence and diameter change functions in the device.

[0065] The shape memory alloy 40 utilizes its temperature deformation characteristics to achieve adaptive adjustment of the flow channel area. The operation is fully automatic, requiring no manual intervention and responding automatically to temperature changes. When the temperature within the flow channel 50 exceeds a certain threshold, it indicates overheating of the molten salt. In this case, the shape memory alloy 40 deforms inward due to the increased temperature, reducing the effective area of ​​the molten salt flow channel and extending the residence time of the molten salt in the heating zone, thus preventing localized overheating. Conversely, when the temperature within the channel falls below the preset threshold, the shape memory alloy 40 deforms outward due to the decreased temperature, increasing the effective area of ​​the flow channel and shortening the residence time of the molten salt, preventing underheating. This adaptive adjustment achieves precise matching between the molten salt's heat exchange time and temperature.

[0066] Temperature sensor 30 continuously collects the real-time temperature of metal block 20 (the temperature of metal block 20 is highly synchronized with the temperature of molten salt in the pipe, accurately reflecting the heating state of molten salt), and feeds back the collected temperature signal to the control module of induction heater 10 in real time. The control module analyzes and processes the received signal, compares it with a preset temperature threshold, and automatically adjusts the input power of induction heater 10. When the temperature is too high, the input power is reduced; when the temperature is too low, the input power is increased, ultimately ensuring that the temperature difference within the flow pipe 50 is controlled within the range of ≤±1℃, achieving constant temperature and uniform heating of molten salt.

[0067] In this way, relying on the spiral flow slot 22 and conical hole 21 structure, the molten salt forms a stable vortex and a constant secondary flow, solving the problem of uneven heating caused by unstable turbulence intensity in existing methods and improving the uniformity of molten salt heating. By using the adaptive deformation adjustment of the flow channel area of ​​the shape memory alloy 40, the residence time of the molten salt for heat exchange is automatically matched without manual intervention, reducing the difficulty of operation. At the same time, it adapts to the heating requirements of molten salt under different temperature conditions, improving the adaptability of the method. Meanwhile, the closed-loop control of the temperature sensor 30 and the control module controls the temperature difference in the pipeline within ±1℃, achieving precise control of the molten salt temperature and avoiding the impact of excessive temperature fluctuations on the performance of the molten salt and subsequent production.

[0068] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A molten salt uniform heating device, for installation in a flowing pipe, characterized in that, include: An induction heater is arranged in a ring and fixedly installed on the wall of the flow pipe; a heating zone is formed inside the flow pipe within the induction heater; A metal block is installed in the heating zone and fixedly connected to the inner wall of the flow pipe; the metal block is provided with a conical hole that is larger at the top and smaller at the bottom and is arranged through the hole; the metal block is provided with a number of spiral flow slots opened on the conical hole, and the spiral flow slots form a secondary flow for molten salt flow; A temperature sensor is installed on the metal block to monitor the temperature of the metal block; the temperature sensor is communicatively connected to the control module of the induction heater. A shape memory alloy is arranged in a ring and fixedly installed on the lower end face of the metal block; the upper end of the shape memory alloy is connected to the lower opening of the tapered hole; the shape memory alloy deforms to change the effective flow area.

2. The molten salt uniform heating device as described in claim 1, characterized in that, The inner wall of the flow pipe has an annular groove, and the induction heater is fixedly installed in the annular groove.

3. The molten salt uniform heating device as described in claim 2, characterized in that, The upper end of the induction heater is higher than the upper end of the metal block, and the lower end of the induction heater is lower than the lower end of the metal block.

4. The molten salt uniform heating device as described in claim 1, characterized in that, The diameter of the upper opening of the tapered hole is equal to the outer diameter of the metal block.

5. The molten salt uniform heating device as described in claim 4, characterized in that, The tapered hole includes a tapered hole section and a straight hole section arranged sequentially from top to bottom, and the upper end of the shape memory alloy is installed in the straight hole section.

6. The molten salt uniform heating device as described in claim 1, characterized in that, The spiral flow slots are multiple in number and are evenly spaced along the circumferential intervals of the conical holes.

7. The molten salt uniform heating device as described in claim 1, characterized in that, The spiral flow slit has a slit depth of 0.5-1.5 mm, a slit width of 0.5-1 mm, and a spiral angle of 20-40°.

8. The molten salt uniform heating device as described in claim 1, characterized in that, The induction heater, the metal block, the temperature sensor, and the shape memory alloy are all multiple and arranged in multiple groups; the multiple induction heaters are arranged sequentially at intervals along the axial direction of the flow pipe.

9. The molten salt uniform heating device as described in claim 1, characterized in that, The temperature sensor is positioned near the lower opening of the tapered hole.

10. A method for uniformly heating molten salt, characterized in that, The molten salt uniform heating device according to any one of claims 1-9 comprises: S1: Activate the induction heater to heat the metal block; S2: Molten salt enters the flow pipe and falls onto the conical hole, forming a vortex motion. Molten salt also enters the spiral flow slot to form a constant secondary flow, making the molten salt heat evenly. S3: When the temperature inside the flow channel is higher than the threshold, the shape memory alloy deforms inward to reduce the flow channel area and prolong the residence time of the molten salt for heat exchange; when the temperature is lower than the threshold, the shape memory alloy deforms outward to increase the flow area and reduce the residence time of the molten salt for heat exchange. S4: The temperature sensor collects the temperature of the metal block and feeds the signal back to the control module. The control module adjusts the input power of the induction heater so that the temperature difference in the flow pipe is ≤±1℃.

Images